Example Code for Arduino-Button Control Relay

Hardware Preparation

• DFRduino UNO R3(SKU: DFR0216) (or similar) ×1
• Amphibious Horizontal Submersible Pump (SKU: FIT0800) ×1
• Gravity: Digital Push Button (Yellow) (SKU: DFR0029-Y) ×1
• Gravity: Digital Push Button (Red) (SKU: DFR0029-R) ×1
• Relay Module with Transparent Case (SKU: DFR0989) ×1
• 3V DC Power ×1
• PH2.0 Wire ×3
• USB Cable ×1
• M-M/F-M/F-F Jumper wires

Software Preparation

• Download Arduino IDE: Click to download Arduino IDE

Wiring Diagram

Connection 1

NO and COM ports will be used in this connection. An external DC power source is required and should be selected according to the load voltage to be connected.

Description:

• Relay: D-----to Mainboard: 8

• Relay: VCC---to Mainboard: 5V

• Relay: GND-----to Mainboard: GND

• Yellow Button: D--to---Mainboard: 2

• Yellow Button: VCC--to---Mainboard: 5V

• Yeloow Button: GND--to---Mainboard: GND

• Red Button: D---to---Mainboard: 3

• Red Button: VCC---to--Mainboard: 5V

• Red Button：GND---to--Mainboard: GND

• Relay Module: NO--to---Pump: positive(red wire)

• Relay Module: COM--to--3V DC Power: positive

• 3V DC Power: Negative--to--Pump: negative(black wire)

Connection 2

This connection is simpler. The pump is directly connected to the OUT and power by VCC, no second power source required.

Description:

• Relay: D-----to Mainboard: 8

• Relay: VCC---to Mainboard: 5V

• Relay: GND-----to Mainboard: GND

• Yellow Button: D--to---Mainboard: 2

• Yellow Button: VCC--to---Mainboard: 5V

• Yeloow Button: GND--to---Mainboard: GND

• Red Button: D---to---Mainboard: 3

• Red Button: VCC---to--Mainboard: 5V

• Red Button：GND---to--Mainboard: GND

• Relay Module: OUT+ --to--Pump: Positive

• Relay Module: OUT- --to--Pump: Negative

Sample Code

The sample code below is suitable for the two connections above. It realizes the function of controlling the relay's ON/PFF through two buttons. Yellow button for pulling in, red button for releasing.

int Relaypin = 8;     // Define relay pin 
int switchPin1 = 2;  // Define yellow button pin  
int switchPin2 = 3;  // Define red button pin 

void setup() { 
 pinMode(Relaypin, OUTPUT);
 pinMode(switchPin1, INPUT);  
 pinMode(switchPin2, INPUT);
}

void loop() {
  if (digitalRead(2)==1) //Determine if the yellow button is pressed 
  {
    delay(50);
    if(digitalRead(2)==1){
      digitalWrite(8, HIGH);//Set relay to high level 
    }
  }
  if (digitalRead(3)==1) //Determine if the red button is pressed 
  {
    delay(50);
    if(digitalRead(3)==1){
      digitalWrite(8, LOW);//Set relay to low level 
    }
  }
}

Result

When the yellow button is pressed, the relay is in pull-in state and the pump starts working; when the red button is pressed, the relay is in releasing state and the pump stops working.